function getXHR(){
	var xhr;
	if (window.ActiveXObject) {
		try{
			xhr = new ActiveXObject("Msxml2.XMLHTTP");
		}catch(e){
			try{
				xhr = new ActiveXObject("Microsoft.XMLHTTP");
			}catch(e){
				alert("你的IE不正常！")
			}
		}
	} else{
		xhr = new XMLHttpRequest();
	}
	return xhr;
}